Present the working principle and structure of a hydrostatic thrust bearing with a circular flat slit fed restrictor,which was designed for variable displacement seat valve distributor of a hydraulic motor. Calculated its bearing capacity and oil film stiffness, analyzed the influence of the height difference between the bearing surface and its circular flat slit fed restrictor on bearing characteristics, compared the circular flat slit fed restrictor hydrostatic thrust bearing with capillary fed restrictor bearing. The results show that the oil film stiffness of the hydrostatic thrust bearing presented in this paper decreases monotone with the thickness of the oil film, and the bearing capacity was more stable than capillary fed restrictor bearing, while the capillary fed restrictor bearing had its best oil film stiffness at its rated working oil film thickness. Hydrostatic thrust bearings with height difference 5 μm and 10 μm were tested,the test results showed that both bearings work with less leakage and friction torque compared with traditional valve plate under 12 MPa and 1000 rpm. The bearing with 5μm height difference is more stable.